Not Applicable
Not Applicable
1. Field of the Invention
The invention relates to a building elevator having an elevator mast, which can be set up vertically, and having an elevator car which can be moved in the vertical direction along the elevator mast and has at least one motor drive with control means.
2. Description of Related Art Including Information Disclosed under 37 CRF 1.97 and 1.98.
Building elevators of this type are known as passenger elevators or as freight elevators, the elevator cars being configured differently in dependence on the carrying load (individuals or freight). It is usually the case that the elevator mast is to be anchored on the ground surface at the set-up location, for which purpose it is equipped with an elevator platform which usually comprises a frame and is set up on the ground surface and, if appropriate, anchored.
For safety reasons, it is absolutely necessary for the space beneath the elevator car, i.e. above the elevator platform, to be secured, in order to avoid the situation where an individual or else objects is/are situated beneath the elevator car when the elevator car moves downward. For this purpose, the elevator platform is usually provided with a fencing-like perimeter protector which bars access to the platform if the elevator car is not situated in its lowermost position. Such a building elevator is known, for example, from DE 196 13 308 A1.
However, such an elevator-platform perimeter protector involves relatively high outlay, that is to say during both construction and dismantling of such a building elevator, and it may also make access to the elevator car more difficult, in particular if the elevator car is designed as a freight carrier. In addition, it is necessary to provide different sizes of perimeter protector for different sizes of elevator cars and elevator-car platforms.
In the case of elevators in buildings which can be moved within an elevator shaft, it is known to arrange, in the region of the door opening, a vertically directed light-emitting grille which covers the door passage in order to ensure that it is not possible for either individuals or objects to be situated in the region of the door opening when the elevator car is traveling (LANGER, Waldemar: Unfallschutz an Lastenaxc3xcfzugen. [Accident protection for freight elevators] In: LIFT-REPORT, 22nd year, 1996, No. 2, March/April, 1996, pages 109, 110). A similar solution is known from JP 070 89 680 A.
The periodical F+H-Report 1994, October, pages 46, 48 xe2x80x9cProgrammierbarer Laser-Scanner revolutioniert den Unfallschutzxe2x80x9d [Programmable laser scanner revolutionizes accident protection] discloses an optoelectronic protection system for monitoring the space in front of dangerous machine tools or the like. This protection system serves for monitoring the access region to a machine otherwise protected by a perimeter protector.
The object of the invention is to develop a building elevator further such that it is ensured, in the simplest possible manner, that it is not possible for any individuals or objects to be situated beneath the elevator car during downward travel of the elevator car.
This object is achieved according to the invention, by a building elevator of the type described in the introduction, in that said building elevator is equipped with an optical monitoring device which monitors the space above the elevator platform set up on a ground surface and is connected to the control means of the motor drive such that the motor drive can be stopped, at least during downward travel of the elevator car, when the space above the elevator platform is not free.
A building elevator equipped in this way means that the need for a high-outlay perimeter protector for the elevator platform can be dispensed with completely. All that is necessary is to provide suitable optical monitoring devices on the borders of the elevator platform, or on the elevator car itself, these devices monitoring as to whether individuals or objects are situated in the space above the elevator platform, and the monitoring device being suitably connected to the control means of the motor drive such that the elevator car is immediately stopped, during downward travel, when individuals or objects are situated beneath the elevator car.
A particularly preferred embodiment is distinguished in that the monitoring device is formed by light barriers, which are preferably designed as infrared light barriers.
In order to ensure particularly reliable monitoring of the space above the elevator platform, it is advantageously provided that the light barriers are arranged at least in certain areas around the outer border of the elevator platform. It may already be sufficient here for light barriers to be provided on two opposite outer edges of the elevator platform.
Provision is made, particularly advantageously in design terms, for the light barriers to be integrated in a frame element which is fastened on the border of the elevator platform. This also makes it possible for existing building elevators to be retrofitted particularly easily simply by a corresponding frame element equipped with light barriers being fitted on the border of the elevator platform.
Alternatively, provision can also be made for light barriers to be integrated in the elevator car.
Instead of light barriers, it is also possible to use at least one laser scanner as the optical monitoring device. Such a laser scanner is known, for example, from the periodical F+H-Report 1994, October, pages 46, 48 xe2x80x9cProgrammierbarer Laser-Scanner revolutioniert den Unfallschutzxe2x80x9d [Programmable laser scanner revolutionizes accident protection].